<div>
  <p>{{ counter.value.count }}</p>
  <button ng-click="counter.increment()">增加</button>
  <button ng-click="counter.decrement()">减少</button>
  <button ng-click="counter.globalIncrement()">全局增加</button>
  <button ng-click="counter.globalDecrement()">全局减少</button>
</div>
